1. Field of the Invention
The invention relates to a design to promote welding in corner regions and more particular to the use of a fin extending outwardly from an outside corner region to promote the proper formation of a weld around such a corner region.
2. Description of the Related Art
Welding is defined as the process of uniting two members by heating them until they are molten and fused, with or without the use of a filler material.
The focus of this application will be directed to welding utilizing a filler material to join two parts which intersect at a corner and for which weld filler must be used to produce a continuous weld around the corner.
Manual welding typically is labor intense and requires a high level of skill on behalf of the welder to efficiently produce a strong high quality weld. Because there are frequently great demands for production placed upon a welder, there is always a desire to improve efficiency by either improving the manner in which the weld is laid or by providing a design which requires less weld material. A design which may permit both of these beneficial features is highly desirable.
Welding material around the corner of a workpiece presents unique problems to which the subject invention is directed. As an example, FIG. 1, which is prior art, illustrates a system by which a first member 10 is secured to a second member 15 by a weld 20. The first member 10 has at least a first side 25 and a second side 30. Each side has an upper portion 32 and a lower portion 34 wherein the lower portion 34 is chamfered relative to the upper portion 32. The weld 20 is fused to the lower portion 34 of at least the first side 25 and the second side 30 of the first member 10. The weld 20 is additionally fused to the surface 35 of the second member 15 thereby securing the first member 10 to the second member 15.
Although defects associated with welding may occur along any portion of the weld 20, the outside corner portions of welds seem to more frequently have defects. The first member 10 which is illustrated as a solid piece, has only outside corners 36, 37, 38, 39. To put this in perspective, if the first member 10 was hollowed out to form a cavity having a perimeter of the same shape as the exterior of the first member 10, the enclosed corners would be referred to as inside corners.
FIG. 2 illustrates a section view of the corner portion of the weld along arrows xe2x80x9c2xe2x80x942xe2x80x9d in FIG. 1. The lower portion 34 of the side 25 is not illustrated in either this view or the view to be discussed with FIG. 3. In FIG. 2, the bottom face 40 of the first member 10 contacts the surface 35 of the second member 15. Weld 20 is used to attach the first member 10 to the second member 15. The metal filler of the weld 20 penetrates the side 25 of the first member 10 and simultaneously penetrates the surface 35 of the second member 15. However, it is not uncommon when welding a corner region to produce a defect known as a rollover, which is also called an overlap. Such a defect is associated with fillet welds and can be produced when either the current of an arc welding machine is too low to properly fuse the second member 15 or the travel speed for the welding process is too low to accept the amount of metal filler being deposited. As a result, a portion of the weld 20 merely flows onto an area of surface 35 and does not fuse with the surface 35. The rollover portion, which is indicated by 50 must be removed to ensure the integrity of the weld 20. Such a defect must be removed by grinding, which requires additional time and labor.
Another type of weld defect which is not uncommon in corner regions is illustrated in FIG. 3 and is referred to as an undercut. FIG. 3 is a view similar to FIG. 2 illustrating a different defect. An undercut is an irregular gouge which is generally found in the upper toe of a horizontal fillet weld. With reference to FIG. 3, the first member 10 has a bottom face 40 which contacts the surface 35 of the second member 15. However, in this situation, the weld 20 droops from a recess or undercut 55 produced in the side 25 of the first member 10. The side 25 of the first member 10 has been melted but has not been refilled with weld material. Most often this defect is caused by improper selected welding conditions such as the electrode angle, travel speed and welding current. It is more likely to occur when attempting to make fillet welds with legs that are more than 0.3 inches in length. Just as a with a rollover defect however, such defects are unacceptable if the integrity of the weld is to be maintained and such defects must be removed. These defects in welds on outside corners may be avoided but only at the cost of a significant increase in welding time and expense.
U.S. Pat. No. 3,832,523 discloses a method for electrical arc welding. In FIG. 12 of that patent, a segment 50 is illustrated which is used on a vertical section for preventing a resulting weld bead which is not completely solidified from drooping. Segment 50 acts as a physical barrier to the weld material. As a result, the section on the plates under segment 50 will not be covered with weld material and therefore the weld will not be continuous. Furthermore, the weld does not extend around a corner and many applications require a continuous bead of weld material around a corner.
U.S. Pat. No. 4,208,563 illustrates a welding method using a break away flux dam in which copper wires are used to surround the weld area and create a pool of molten weld metal with a top layer of flux. While this illustrates a manner of containing a weld, it once again does not address a weld around a corner with a continuous bead of weld material.
A design is needed which permits a welder to secure a first member, which may be metal, having outside corners to a second member, which also may be metal, while applying a continuous weld around the corners of the member in an expedient fashion that will provide a weld with integrity and minimize the potential for producing defects such as rollover and undercut while also reducing the time and cost of welding.
While such a design is applicable to welding any two members with outside corners, it is of particular significance in securing a bit block or base to a rotatable member, such as a drum, wheel or chain, for equipment used in construction operations, such as road planning or trenching, or in mining operations, such as coal mining.
One embodiment of the invention is directed to a first member for welding to a second member wherein the first member is comprised of a body having a top, a bottom and a face on the bottom for contacting a surface on the second member. The first member has a plurality of sides between the top and the bottom including a first side adjacent to the face, and a second side adjacent to the face. The first side and the second side converge to define an outside corner region between the top and the bottom. A fin extends from the corner region to promote the formation of a weld in the corner region.
A second embodiment of the invention is directed to a system which includes the first member just described mounted upon a second member using weld material.
A third embodiment of the invention is directed toward one application of the first member as a metal block for mounting upon a metal drum used in mining or construction operations.
A fourth embodiment of the invention is directed toward one application of a system including the first member as a metal block mounted to a metal drum and secured with weld material for use in mining or construction operations.